1. n. [Formation Evaluation]
A log recorded using an electrical wireline. In this sense, the term refers to any log recorded on a wireline, whether it measures an electrical quantity or not. The term dates from the early days of logging when the only logs were the spontaneous potential and resistivity from conventional electrode devices.
See: electrode device, logging tool, resistivity log, spontaneous potential
2. n. [Formation Evaluation]
A wireline log of formation resistivity produced by a simple, unfocused arrangement of current emitting and measure electrodes. Conventional electrical devices have four electrodes-current emitting (A), current return (B), measure (M) and measure reference (N)-which may be placed in different configurations. The two most common configurations are the normal and lateral. The currents used are low frequency, typically less than 500 Hz. H.G. Doll recorded the first electrical log on September 5, 1927, in the Pechelbronn field, Alsace, France.
Alternate Form: electrical survey
See: departure curve, electrode device, electrode resistivity, wireline log